- Delete TurnCtx struct (was progressively populated with optional nil fields)
- Convert run(), streamResponse(), execToolCalls(), execBatch(), execOne(),
trackErrors(), retryCountdown() to Agent methods
- Extract autoCompact() and popInject() as Agent methods
- turn.go now installs a turn-scoped output handler wrapper instead of
building TurnCtx closures
- context.Context is now passed as plain context.Context, not smuggled
with unrelated state
Add history compaction tests:
- TestBuildCompactedHistory_OrphanedToolWalkback: verifies walk-back logic
prevents orphaned tool messages at hot zone boundary
- TestBuildCompactedHistory_NoOrphanAtBoundary: verifies tool messages
always have preceding assistant with tool_calls
23f3a6092b